1. Field of Invention
The present invention is directed to apparatuses for restricting fluid flow through a conduit or tubular member within oil and gas wells and, in particular, to apparatuses having one or both of a shape-memory seat or plug element that facilitate either passing the plug element through a seat or restriction disposed in the tubular member, or facilitate landing the plug element on the seat.
2. Description of Art
Ball seats are generally known in the art. For example, typical ball seats have a bore or passageway that is restricted by a seat. The ball or plug element is disposed on the seat, preventing or restricting fluid from flowing through the bore of the ball seat and, thus, isolating the tubing or conduit section in which the ball seat is disposed. As force is applied to the ball or plug element, the conduit can be pressurized for tubing testing or tool actuation or manipulation, such as in setting a packer. Ball seats are used in cased hole completions, liner hangers, flow diverters, frac systems, and flow control equipment and other systems.
Although the terms “ball seat” and “ball” are used herein, it is to be understood that a drop plug or other shaped plugging device or element may be used with the “ball seats” disclosed and discussed herein. For simplicity it is to be understood that the terms “ball” and “plug element” include and encompass all shapes and sizes of plugs, balls, darts, or drop plugs unless the specific shape or design of the “ball” is expressly discussed.